You are interested in integral membrane proteins of the plas

You are interested in integral membrane proteins of the plasma membrane. You treatments western blotting 4 individual proteins isolated after the following CONTROL: From untreated cells SET 1: Intact cells treated with a protease enzyme. SET 2: cells made permeable to proteins by treatment with small amounts of detergent before treatment with the protease. Four different proteins (W, X, Y and Z) are analyzed on SDS-PAGE Why do the bands in the \"C\" lanes run with different mobilities? which protein is exposed only on the exterior of the cell? Explain. hich protein is exposed in the interior AND the exterior of the cell? Explain. What is the minimum size (in kD) of this protein? what can you say about the other two proteins in terms of topology? Markers in Kilodaltons C 1 2 C 1 2 C 1 2 C 1 2 115 62 50/48 37 15

Solution

The bands in C lane runs with different mobilities because all different bands have different size. So, due to the difference in sizes of all four proteins, their bands runs on PAGE with different mobilities.